Students of a vocational school in Lanzhou, Southwest China’s Gansu province show a globe-shaped Luban lock made by themselves on November 24, 2016. The traditional Chinese puzzle is formed by 12 precise metal parts. Lu Ban Lock is an educational toy invented by a famous ancient Chinese carpenter named Lu Ban that is based on mortise and tenon joints. Each piece of the lock is interconnected without fixtures and players have to unlock the gadget and put the pieces back together. (Photo: China News Service/ Liu Yutao)
